Write one difference between Porifera and Coelenterata.

Write one difference between Arthropoda and Mollusca.

Write one difference between Platyhelminthes and Nematoda.

Draw a neat diagram of a fish and label the five kinds of fins, operculum and mouth. Answer the following questions :

1. Name the phylum and the class to which fishes belong.
2. What is the one advantage of their specific body shape ?
3. Do they breathe through nostrils ? If not, mention the role of nostrils.
4. Mention the breathing and locomotory structures in fishes.
5. Give any two examples of fishes.